Aerodynamics can play an important role in a ground vehicle's dynamic behavior at speed. Positive aerodynamic lift is generally undesirable because the corresponding reduction in traction to the tire(s) can be reduced below the levels required for safe cornering, braking, or acceleration. To counteract such tendencies, a number of aerodynamic elements such as spoilers or wings are known to create negative lift, or downforce, to increase the vehicle's limit of adhesion.
However, in many applications, spoilers or wings placed above the vehicle to create downforce have a notable drag penalty expressed as a lift-to-drag (L/D) ratio. This means with increasing downforce from the addition of or increasing angle-of-attack (AoA) of a wing, there is a corresponding increase in power required to maintain speed or acceleration rate as well as increase in fuel consumption. There is a continuing need for new ways to modulate ground vehicle aerodynamics.